SOME READERS understood right away what I meant last week when I said that John McCain has the misfortune to be running against Luke Skywalker. But others are still scratching their heads, wondering what in the world I was talking about.

I was talking about Barack Obama. I think his story has been so compelling for so many people because it taps into one of our most profound myths.

Some myths are simply stories; others are based on real people and events. But the essence of any myth is that it embodies our deepest yearnings and desires.

And Obama’s myth is a tried-and-true one. The late folklorist Joseph Campbell called it “the hero’s journey,” and it’s found in every culture, from Moses, David and Odysseus to Luke Skywalker, Frodo and Harry Potter.

It’s both a literal journey and an inward voyage of self-discovery. The hero begins as a callow youth — often one who has lost one or both parents — who has no idea who he really is.

The journey consists of a series of trials that teach him his true destiny and reveal powers that he didn’t know he had. These trials are usually epic struggles against seemingly invincible monsters.

David fought the giant Goliath, Odysseus fought the one-eyed Cyclops, and Obama has been waging a marathon battle against the dreaded two-headed Billary.

At the end of the journey, armed with enhanced power and self-knowledge, the hero returns home and saves the world.

But there are two big lessons he has to learn first.

The first one is a paradox: In order to gain power and wield it for good, he has to renounce power.

Frodo gave up the Ring of Power. Luke Skywalker refused to use the dark side of The Force. And Obama is rewriting the rules of the game by creating a new paradigm.

Every time he passes up the temptation to respond in kind to Clinton’s barbs, he paints her into a corner. Despite her wins Tuesday night, her attacks will inevitably rebound and push up her own negative ratings. And his refusal to get down-and-dirty wins him even more admirers.

As a friend of mine, who is volunteering for Obama, wrote me, “The most important principle is that the end does not justify the means. It is a transformation from the Machiavellian era we have been operating in for many decades. We believe that if the means are not consistent with the ends, the ends will never be achieved because they will be too compromised and tarnished by the process.”

The other big lesson the hero has to learn is that it’s not about him; it’s about something much bigger.

For Moses and David, it’s the will of God. For Luke Skywalker, it’s The Force. And for Obama, it’s the millions of volunteers who have flocked to his standard. Watch him next time he addresses a crowd. He feeds off their energy, and they feed off his.

They love him because he’s taught them to love themselves — specifically, that part of themselves that is responding to the better angels of their nature.

Clinton’s supporters think she would be the best president. Ditto for McCain’s. But the Obamaphiles want something more: They believe the country is going down the tubes, and they consider it their patriotic duty to lay aside all the old differences that have divided us for the past 40 years and work together for the common good.

“It’s such a bottom-up system, driven by a vision of what this country can be, much more than being centered solely on Obama, although his approach is deeply shared,” says my friend. “That is a lot of what makes it so thrilling. It’s like experiencing the change we are trying to create.”

Or, as an ancient Chinese proverb puts it, “Good rulers are loved and praised. The next best are feared. But when the very best rulers achieve their purpose, the people say, ‘We did it ourselves.'”